Certain travel industry groups, notably the United States-based airline industry, developed computer-based reservation system databases in the period generally corresponding to 1965 to 1975, and in which reservation systems flight information was based on the traveler's desired origination-to-destination journey. The air travel industry settled on several similar systems, including COVIA (United Airlines, USAIR); DATAS II (Delta Airlines); PARS (TWA and Northwest); SABRE (American Airlines); and SYSTEMONE (Texas Air Corporation) in order to enable reference to schedule and tariff information among many parties. The data was arranged, organized, and stored in a format generally corresponding to the dominant travel routing patterns, in which a carrier accepted a passenger at a first, origination location and discharged the passenger at a terminal or destination location. The data is generally stored in several databases within each reservation system: schedules, tariffs, and rules. Booking a flight involves creating a computer record called the Passenger Name Record (PNR) of data from each of these sub-databases. As flights are booked for different carriers, a teletype message with the flight information is passed between airlines via ARINC, an air travel data communication service. Reservation data may also bypass ARINC and be exchanged directly between airline computers. The PNR is used to generate tickets, itineraries, and the "interface record" that is used by travel agency accounting systems. Information on flights flown by travelers may be obtained from the airlines in three ways: via agency accounting systems, branch interface, or the Airline Reporting Corporation.
Within agency accounting systems, the travel agencies receive the interface record in on-site accounting systems which record the amount payable due to the airline issuing the ticket and the receivable due from the client. This reservation data may also be used to monitor agent productivity and to furnish clients with some information on their expenditures.
With the branch interface, third-party groups, such as airline ticket auditors may establish a "branch access" with the airline reservation systems to receive the Passenger Name Record. Data from the PNR may then be placed into secondary computer systems for analysis and reporting.
With the Airline Reporting Corporation, airline reservation data is also provided to groups, such as credit card companies, which are involved with the Airline Reporting Corporation for the payment of airline tickets. These groups also place the data into secondary computer systems for reporting purposes.
In domestic air travel, the need for multiple stops for fuel, passengers, etc. was relatively unimportant during the inauguration of the reservation databases, as the travel companies were anxious to meet the passengers, demands for direct, and preferably non-stop flights from origin to destination. Occasionally, the vehicle would make such a stop if the intermediate landing could add revenue without unneeded delay, or otherwise to provide regulated service; these flights often offered slightly reduced fares to compensate the passenger for the inconvenience.
For these essentially direct flights, no change of planes was necessary, and the reservation systems database PARS format display of the flight data could be a single-line entry or display (whether on paper or on a computer display screen), showing flight number and origination, destination, departure and arrival times, class of service, price, and so forth. Deriving the distance traveled presented little or no problem as the flights were essentially direct or shortest path in nature, and the cost and time information were implicit from the departure/arrival times and ticket office.
Beginning about 1975, however, the travel industry, and especially the United States-based airline industry underwent a fundamental change in the nature of operations, in which fare competition forced greater emphasis on economically transporting passengers and less on travel time and convenience for the traveler. This change was accompanied by the substitution of a hub-and-spoke, multiple-segmented arrangement for the previous conventional direct flight arrangement. That is, regional airports became "hubs," and the flight paths were between the hubs rather than direct from origin to destination.
At the same time, the PARS format data display and presentation method became outdated because many trips became multiple-segment flights, often with change of aircraft. Since the passenger paid only for the trip cost on the basis of the origin-to-destination, not the total of the cost of the individual flight segments at their normal prices, this total trip cost information could not be divided among the segments without severe distortion or overload of the computerized database.
With the advent of the hub-and-spoke system, each travel segment between hubs required a separate data display line. The segments were listed in order, and the ticket price information listed on only one of the segment lines. Thus the PARS format data was forced to require multiple lines for the full, origin-to-destination data as the schedule information became more complex in order to show the movement between the hubs. Only one segment, usually the terminal segment, included price information. Total travel time could be determined for each of the segments, but departure to arrival time, and especially flight travel time, became distributed among the various segment lines, and thus obscure or hidden, making travel per unit of time exceedingly difficult to determine when the traveler's time expense became a factor. Determining real costs for travel became extremely complicated and time-consuming as extracting the information and determining true travel parameters is an essentially judgment-based activity relying on information which often changes, and generally changes too frequently to enable reliable human analysis.
An example of this is demonstrated by a flight from New York/Kennedy to Los Angeles International airport (respectively, NYC and LAX). A non-stop flight might be listed with the following reservation format information (certain information is omitted here for simplicity, i.e., departure/ arrival times, etc.:
______________________________________ Origin Destination Price ______________________________________ NYC LAX $900.00 ______________________________________
A similar direct flight might stop briefly in Kansas City with no discernible difference in origination-to-destination travel distance, having a slightly reduced fare, and resulting in the following reservation system format information:
______________________________________ Origin Destination Price ______________________________________ NYC LAX (KCY) $750.00 ______________________________________
Under the hub-and-spoke system, a similar flight might originate in New York, change planes in Atlanta, and then go on to Los Angeles. Such a hub-and-spoke trip will have a much longer origination-to-destination travel distance, have a similar fare, and result in the following information:
______________________________________ Origin Destination Price ______________________________________ NYC ATL $000.00 ATL LAX 750.00 ______________________________________
A more complex series of segments might include a first stop in Atlanta, travel to Denver with a change of airplanes, then on to Los Angeles. This might be displayed as follows:
______________________________________ Origin Destination Price ______________________________________ NYC ATL $000.00 ATL DEN 000.00 DEN LAX 750.00 ______________________________________
Clearly, segment data is more difficult to present. It is not displayed on a single line but rather on multiple lines in a manner which greatly complicates the determination of associated data.
Flight time information for a given flight is also obscured; a given non-stop flight might be listed with the following format time information:
______________________________________ Origin Destination Price Depart Arrive ______________________________________ NYC LAX $900.00 08:15 AM 1:15 PM ______________________________________
Now examining a similar flight, again with a stop at Kansas City, the following information might be displayed:
______________________________________ Origin Destination Price Depart Arrive ______________________________________ NYC LAX (KCY) $750.00 08:15 AM 2:00 PM ______________________________________
Here, the slight difference is obviously an accumulation of the additional landing, ground, and take-off time for the Kansas City stop, which information is again easily determined. The total travel time in this example is, simply, 5 hours and 45 minutes plus 3 hours for the time zone conversion.
A hub-and-spoke trip stopping in Atlanta, however, might be displayed:
______________________________________ Origin Destination Price Depart Arrive ______________________________________ NYC ATL $000.00 8:15 AM 11:15 AM ATL LAX $750.00 12:15 PM 5:15 PM ______________________________________
And a flight from New York to Los Angeles with a stop in Atlanta and a change of planes in Denver may be displayed as:
______________________________________ Origin Destination Price Depart Arrive ______________________________________ NYC ATL $000.00 8:15 AM 11:15 AM ATL DEN 000.00 12:15 PM 1:15 PM DEN LAX $750.00 3:15 pM 6:45 PM ______________________________________
The total flight time of the individual segments is greater than the flight time of either a non-stop or a direct, one-stop flight, and without indicating arrival/departure/arrival delays for the segments, the information available from the reservation system database distorts the total travel time unless origination departure to destination arrival times are separately available; they are ordinarily displayed on separate reservation lines, adding difficulty in determining the total travel time determination. Multiple stops in different time zones, especially on an East to West flight, tends to obscure the flight time when only segment flight data is available.
The segment data available does not permit determining the shortest distance between points. Cost-per-unit time and/or distance and both total travel time and time-per-unit determinations are very difficult to obtain from the above example. Without a standardized reference of costs, such as cost per mile or kilometer, and without an accumulated or other time reference, the cost per mile and cost per hour cannot readily be determined.